URINARY EXCRETION AND TISSUE LEVELS OF CATECHOLAMINES DURING CHRONIC AMPHETAMINE INTOXICATION

Administration of 16 mg/kg of dl-amphetamine sulphate twice daily caused a 3- to 5-fold increase in the urinary output of noradrenaline and adrenaline in rats. Bilateral splanchnic denervation abolished the urinary adrenaline response to amphatemine. After an initial increase in urinary catecholamines there was a gradual decrease during chronic amphetamine administration. An increased survival after otherwise lethal doses of amphetamine was observed. No evidence of an increased metabolic inactivation of amphetamine in chronically treated animals as measured by the pattern of distribution of urinary metabolites of injected d-amphetamine-3H was found. Brain and heart noradrenaline were decreased to 70% of the control level after a single amphetamine injection (20 mg/kg). After chronic administration of amphetamine for 7 and 30 days the levels were reduced to 50% and 40% respectively. In addition, brain dopamine which increased after acute administration was depleted to about 50% of the control level in chronically amphetamine-treated rats. © 1968 Springer-Verlag.